peer: introduce a limitedarguments attributes When set to True, it signal that the peer cannot receive too larges arguments and that algorithm must adapt. This should only be True for http peer that does not support argument passed as "post". This will be useful to unlock better discovery performance in the next changesets. I am using a dedicated argument because this is not really a usual "capabilities" things. An alternative approach would be to adds a "large-arguments" to all peer, but the http peers. That seemed a bit too hacky to me.

verify: also check full manifest validity during verify runs Before this changes, `hg verify` only checked if a manifest revision existed and referenced the proper files. However it never checked the manifest revision content itself. Mercurial is expecting manifest entries to be sorted and will crash otherwise. Since `hg verify` did not attempted a full restoration of manifest entry, it could ignore this kind of corruption. This new check significantly increases the cost of a `hg verify` run. This especially affects large repository not using `sparse-revlog`. For now, this is hidden behind the `--full` experimental flag.

verify: introduce an experimental --full flag The flag currently has no effect, see next changeset for details. We introduce the flag as experimental to keep the freedom of changing our mind on the final UI. Note: this patch highlight a small but in `hg help`. An option section is generated even if no option are visible.

verify: introduce a notion of "level" Some checks are slower than others, to help the user to run the checks he needs, we are about to introduce new flag to select faster vs deeper runs. This put the scaffolding in place to do this.

tests: split out separate test for issue5020 The test was added to the existing setup in 41f6af50c0d8 (merge: fix crash on criss cross merge with dir move and delete (issue5020), 2017-01-31). I'm about to make a change that affects that test and it's much easier to follow if the test case for issue5020 is a separate test case. The separate test case is based on what mpm provided in comment 12 on the issue. `hg diff -r 41f6af50c0d8^ tests/test-merge-criss-cross.t` after this patch is pretty small (besides the added test). It's probably easier for reviewers to look at that than to try to understand the diff itself (I don't understand it). Differential Revision: https://phab.mercurial-scm.org/D6243

tests: avoid a rename/delete conflict when updating in test-narrow-update.t After the upcoming rewrite of mergecopies(), this test would otherwise (accurately) start warning about "inside/f1 was deleted and renamed". Differential Revision: https://phab.mercurial-scm.org/D6254

tests: delete unused function in test-rename-merge2.t Differential Revision: https://phab.mercurial-scm.org/D6253

tests: make merge conflicts explicit in `hg annotate` tests We were using `true` as merge tool. I think it makes the test easier to understand if we make the conflicts explcit. It also papered over a conflict that shouldn't have been a conflict (just a bug in copy tracing). I've marked that "BROKEN". Differential Revision: https://phab.mercurial-scm.org/D6252

narrow: make warning about possibly dirty files respect ui.relative-paths Differential Revision: https://phab.mercurial-scm.org/D6264

merge: forgot to pull before release These two changes should be part of 5.0, but we are fine leaving them out of the RC.